The adaptive function and social integration of mentally retarded individuals may be compromised by maladaptive behaviors or by neurological side effects of certain treatment modalities. The proper evaluation of such problems has not previously been undertaken in a systematic, prospective fashion. Therefore, the risks and consequences of certain long-term treatment measures are not properly understood. This proposal is concerned with the development of an appropriate evaluation technology for retarded individuals in intensive behavioral and habilitative treatment programs. It is concerned with clients in three representative settings: a public regional residential center, a private residential center and a community-based treatment program. The effects of treatment on adaptive function, behavior, neuropsychologic and neurologic status will be measured.